Effect of temperature on development and survival of immature stages of Bactrocera invadens (Diptera: Tephritidae)

Abstract

The development and survival of immature stages of Bactrocera invadens Drew, Tsuruta and White (Dipt.: Tephritidae), a new invasive fruit fly pest in Africa, was studied in the laboratory at five constant temperatures of 15°C, 20°C, 25°C, 30°C and 35°C and photoperiod of L12:D12. The developmental time of eggs was 5.71 days at 15°C, decreasing to 1.24 days at 35°C. Larval development periods decreased from 35.95 days at 15°C to 6.64 days at 35°C. Pupal development at 15°C took 34.08 days while no adults emerged at 35°C, this being the most lethal temperature. The longest total development period occurred at 15°C (75.74 days) and was shortest at 30°C (17.76 days). The linear model provided a reliable fit of development rates vs. temperature for the immature stages. Lower developmental thresholds that were estimated from linear regression equations for the egg, larva and pupal stages were 8.8, 9.4 and 8.7, respectively. Total degree‐day (DD) accumulation was estimated at 376 DD for development from egg to adult emergence. The highest adult survival given as the mean of emergence from a cohort of 50 eggs occurred at 20–30°C. At the egg stage, survivorship was highest at 20–30°C and at the larva and pupa stages, it was at 25°C. The practical implication of the findings is discussed in relation to mass rearing of B. invadens and understanding its biology and ecology.

Species composition and community structure of fruit flies (Diptera: Tephritidae) across major mango-growing regions in Uganda

“…Cucurbits are not a common crop in the NMF. The infrequent encounter of the other species that have been hitherto reported (Nakasinga, 2002) is probably due to the monophagous nature of their host range among indigenous fruits (Ekesi et al, 2006) or due to continued displacement (Mwatawala et al, 2006a;Rwomushana et al, 2008). Hence, the geographical variations observed in our study may be less important since ecological displacement by Bactrocera is taking place.…”

“…Besides being an important pest, it also seems to have an impact on the indigenous fruit fly fauna in commercial fruit produce, as has been detailed here, and in the region (Ekesi et al, 2006). Bactrocera invadens displacement of other species has been attributed to competition (Rwomushana et al, 2008), and annual and within-habitat spatial distribution activity (Mwatawala et al, 2004;Drew et al, 2005;Mwatawala et al, 2006a,b;Rwomushana et al, 2008;Nboyine et al, 2012;Geurts et al, 2012).…”

“…This might be explained by differences in host preference for each genus, although we were unable to investigate this during the course of the study. For instance, the majority of the species of the Bactrocera and Dacus genera encountered in this study are well-known economic pests attacking a broad diversity of cucurbit fruits (Mwatawala et al, 2006a;Rwomushana et al, 2008). Therefore, the dominant representation by genus Dacus in the LVC and WMHF is probably due to the presence of cucurbit hosts in the area.…”

“…Bactrocera invadens was reported to be displacing indigenous Ceratitis species of mango, constituting up to 98 and 97% of the total population in Kenya (Rwomushana et al, 2008) and Tanzania (Mwatawala et al, 2006a), respectively. The observed dominance in horticulture monocultures has also been demonstrated in West Africa (Vayssières et al, 2009).…”

“…To support the development of a robust fruit fly management programme in Uganda, and to complement efforts in other countries of East Africa, it is prudent that the fruit fly fauna in Uganda is described. In East Africa, specifically Kenya and Tanzania, the fruit fly fauna has been well described (Ekesi et al, 2006;Mwatawala et al, 2006a,b;Rwomushana et al, 2008;Mwatawala et al, 2009;Geurts et al, 2012), but less so for Uganda, where two studies have described the fruit fly fauna in the country (Nakasinga, 2002) but were very limited in geographical scope. The Ugandan studies recorded Ceratitis species as the most pestiferous fruit flies.…”